JP2021063972A - Polarizing plate with retardation layer and adhesive layers, and organic electroluminescence display device using the same - Google Patents

Abstract

To provide a polarizing plate with a retardation layer and adhesive layers, which offers superior durability in high-temperature high-humidity environments and significantly suppresses discoloration when used in organic EL display devices.SOLUTION: A polarizing plate with a retardation layer and adhesive layers is provided, comprising: a polarizing plate comprising a polarizer and a protective layer provided at least on a viewer side of the polarizer; a retardation layer bonded to a surface of the polarizing plate on a side opposite the viewer side via a first adhesive layer; and a second adhesive layer provided on the retardation layer on a side opposite the polarizing plate as the outermost layer. The first or the second adhesive layer contains a UV absorber, where the UV absorber content in the first or the second adhesive layer is 1-12 wt.%. The polarizing plate with the retardation layer and adhesive layers has a transmittance of 5% or less for the 380-nm wavelength.SELECTED DRAWING: Figure 1

Description

The present invention relates to a polarizing plate with a retardation layer and an adhesive layer, and an organic electroluminescence (EL) display device using the same.

In recent years, with the spread of thin displays, displays (organic EL display devices) equipped with organic EL panels have been proposed. Since the organic EL panel has a highly reflective metal layer, problems such as reflection of external light and reflection of the background are likely to occur. Therefore, it is known that these problems can be prevented by providing a circular polarizing plate on the visual side (for example, Patent Documents 1 to 3). However, there is a problem that the circular polarizing plate provided in the organic EL display device is easily decolorized. Further, in the circular polarizing plate, improvement of durability in a high temperature and high humidity environment is continuously required.

Japanese Unexamined Patent Publication No. 2003-31239 JP-A-2002-372622 Japanese Patent No. 3325560

The present invention has been made to solve the above-mentioned conventional problems, and its main purpose is to have excellent durability in a high temperature and high humidity environment, and to remarkably suppress decolorization when applied to an organic EL display device. It is an object of the present invention to provide a polarizing plate with a retardation layer and a pressure-sensitive adhesive layer.

The polarizing plate with a retardation layer and a pressure-sensitive adhesive layer of the present invention includes a polarizing plate, a polarizing plate containing a protective layer at least on the viewing side of the polarizing element, and a first pressure-sensitive adhesive on the side opposite to the viewing side of the polarizing plate. It has a retardation layer bonded via a layer and a second pressure-sensitive adhesive layer arranged as an outermost layer on the opposite side of the retardation layer to the polarizing plate. The first pressure-sensitive adhesive layer or the second pressure-sensitive adhesive layer contains an ultraviolet absorber, and the content of the ultraviolet absorber in the first pressure-sensitive adhesive layer or the second pressure-sensitive adhesive layer is 1% by weight to 12% by weight. By weight%. The polarizing plate with the retardation layer and the pressure-sensitive adhesive layer has a transmittance of 5% or less at a wavelength of 380 nm.
In one embodiment, in the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer, the polarizer and the retardation layer are bonded to each other via the first pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer contains an ultraviolet absorber.
In one embodiment, in the one embodiment, the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer contains acrylic acid as a monomer component of the base polymer. In one embodiment, the acrylic acid content in the monomer component is 0.1% by weight to 7% by weight. In one embodiment, the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer further comprises a radical generator.
In one embodiment, the solubility of the first pressure-sensitive adhesive layer in ethyl acetate at 25 ° C. is 2 g / 100 g to 70 g / 100 g.
In one embodiment, the first pressure-sensitive adhesive layer has a molar extinction coefficient of 400 L / (mol · cm) or more at a wavelength of 380 nm.
In one embodiment, the moisture permeability of the protective layer of the viewing side is a 200g / m 2 · ^24h or more, greater than the moisture permeability of the retardation layer.
According to another aspect of the present invention, an organic electroluminescent display device is provided. This organic electroluminescence display device includes the above-mentioned retardation layer and a polarizing plate with an adhesive layer.

According to the embodiment of the present invention, in the polarizing plate with the retardation layer and the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer or the polarizing plate with the retardation layer and the pressure-sensitive adhesive layer in which the polarizing plate and the retardation layer are laminated is used as an image display cell. By introducing a predetermined amount of ultraviolet absorber into the adhesive layer for bonding, it has excellent durability in a high temperature and high humidity environment, and decolorization is remarkably suppressed when applied to an organic EL display device. A polarizing plate with a retardation layer and an adhesive layer can be realized.

It is the schematic sectional drawing of the polarizing plate with the retardation layer and the pressure-sensitive adhesive layer by one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

(Definition of terms and symbols)
Definitions of terms and symbols herein are as follows.
(1) Refractive index (nx, ny, nz)
"Nx" is the refractive index in the direction in which the in-plane refractive index is maximized (that is, the slow-phase axis direction), and "ny" is the in-plane direction orthogonal to the slow-phase axis (that is, the phase-advance axis direction). Is the refractive index of, and "nz" is the refractive index in the thickness direction.
(2) In-plane phase difference (Re)
“Re (λ)” is an in-plane phase difference measured with light having a wavelength of λ nm at 23 ° C. For example, "Re (550)" is an in-plane phase difference measured with light having a wavelength of 550 nm at 23 ° C. Re (λ) is obtained by the formula: Re (λ) = (nx−ny) × d, where d (nm) is the thickness of the layer (film).
(3) Phase difference in the thickness direction (Rth)
“Rth (λ)” is a phase difference in the thickness direction measured with light having a wavelength of λ nm at 23 ° C. For example, "Rth (550)" is a phase difference in the thickness direction measured with light having a wavelength of 550 nm at 23 ° C. Rth (λ) is obtained by the formula: Rth (λ) = (nx−nz) × d, where d (nm) is the thickness of the layer (film).
(4) Nz coefficient The Nz coefficient is obtained by Nz = Rth / Re.
(5) Angle When referring to an angle herein, the angle includes both clockwise and counterclockwise with respect to the reference direction. Therefore, for example, "45 °" means ± 45 °.

A. Overall Configuration of Polarizing Plate with Phase Difference Layer and Adhesive Layer FIG. 1 is a schematic cross-sectional view of a polarizing plate with a retardation layer and an adhesive layer according to one embodiment of the present invention. The polarizing plate 100 with the retardation layer and the pressure-sensitive adhesive layer in the illustrated example includes the polarizing plate 10, the retardation layer 30 bonded to the polarizing plate 10 via the first pressure-sensitive adhesive layer 20, and the retardation layer 30. It has a second pressure-sensitive adhesive layer 40 provided as an outermost layer on the side opposite to the polarizing plate 10. The second pressure-sensitive adhesive layer 40 makes it possible to attach the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer to the image display cell. The polarizing plate 10 includes a polarizing element 11 and a protective layer (visible side protective layer) 12 at least on the viewing side of the polarizing element 11. In the illustrated example, the protective layer (inner protective layer) 13 is provided on the side opposite to the visible side of the polarizer 11, but the protective layer 13 may be preferably omitted. That is, the polarizer 11 and the retardation layer 20 can be bonded to each other via the first pressure-sensitive adhesive layer 20. In the configuration in which the inner protective layer 13 is omitted, the effect of the embodiment of the present invention is remarkable. Practically, it is preferable that a release film is temporarily attached to the surface of the second pressure-sensitive adhesive layer 40 until the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer are used. By temporarily adhering the release film, it is possible to protect the second pressure-sensitive adhesive layer and form a roll of the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer.

In the embodiment of the present invention, the first pressure-sensitive adhesive layer 20 or the second pressure-sensitive adhesive layer 40 contains an ultraviolet absorber. The UV absorber content in the first pressure-sensitive adhesive layer 20 or the second pressure-sensitive adhesive layer 40 is 1% by weight to 12% by weight, preferably 2% by weight to 10% by weight, and more preferably 3% by weight. ~ 7% by weight. If the content of the ultraviolet absorber is too large, the durability of the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer in a high-temperature and high-humidity environment may be insufficient. If the content of the ultraviolet absorber is too small, the UV absorption capacity of the polarizing plate as a whole becomes insufficient, and the organic EL panel containing an organic substance may be deteriorated. Preferably, the first pressure-sensitive adhesive layer 20 contains an ultraviolet absorber. With such a configuration, deterioration of the retardation layer in a high temperature and high humidity environment can be suppressed. When the ultraviolet absorber is contained only in the second pressure-sensitive adhesive layer, bleed-out, peeling, etc. may occur in addition to the deterioration of the retardation layer. Further, in the embodiment of the present invention, the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer have a transmittance of 5% or less, preferably 4% or less, and more preferably 3.5% or less at a wavelength of 380 nm. It is more preferably 2.5% or less. On the other hand, the transmittance at a wavelength of 380 nm is preferably 0.4% or more. If the transmittance at a wavelength of 380 nm is too low, it is necessary to add a large amount of an ultraviolet absorber, so that the durability of the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer in a high-temperature and high-humidity environment may be insufficient. If the transmittance at a wavelength of 380 nm is too high, the organic EL panel may deteriorate.

As described above, in the embodiment of the present invention, the protective layer 13 may be preferably omitted. In this case, the moisture permeability of the protective layer 12 is larger than the moisture permeability of the retardation layer 20. When the protective layer 13 is present, the moisture permeability of the protective layer 12 is larger than the moisture permeability of the protective layer 13 and the moisture permeability of the retardation layer 20, whichever is smaller; the protective layer 13 is present and When the retardation layer 20 is an orientation-solidified layer of a liquid crystal compound, the moisture permeability of the protective layer 12 is larger than that of the protective layer 13. The present inventors face a new problem that the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer are decolorized when the polarizing plate with the retardation layer and the pressure-sensitive adhesive layer is applied to an organic EL display device. As a result of diligent studies, it was discovered that the cause of the decolorization was ammonia (substantially ammonium ions) generated from the organic EL panel. Furthermore, as a result of diligent studies on means for suppressing decolorization due to ammonia, the decolorization is remarkable by blocking the ammonium ions that have invaded the polarizer as much as possible and discharging the ammonium ions that have invaded as much as possible. I found that it can be suppressed. Based on these findings, by reducing the moisture permeability of the protective layer or retardation layer on the side opposite to the viewing side (organic EL panel side), ammonium ions that invade the polarizer are blocked as much as possible, and the viewing side (organic). By increasing the moisture permeability on the side far from the EL panel), it was possible to discharge as much ammonium ions as possible that had invaded, and this new problem was solved. The protective layer of the polarizer is designed to reduce the moisture permeability of the outer (visual side) protective layer because the main purpose is to protect the polarizer from moisture (water vapor). The embodiment of the present invention is based on such a technical idea completely opposite to the common general technical knowledge in the art.

When the protective layer 13 is omitted, the difference between the moisture permeability of the moisture permeability and the phase difference layer 20 of the protective layer 12 is preferably 200g ^/ m 2 · 24h or more, more preferably 220g ^/ m 2 · 24h or more , and still more preferably at 250g ^/ m 2 · 24h or more, and particularly preferably 300g ^/ m 2 · 24h or more. The upper limit of the difference may be, for example, 600g ^/ m 2 · 24h. When the difference is within such a range, decolorization of the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer can be suppressed more satisfactorily.

Moisture permeability of the protective layer 12 is 200g ^/ m 2 · 24h or more, preferably 300g ^/ m 2 · 24h or more, more preferably 330g ^/ m 2 · 24h or more, more preferably 360 g / ^{m 2} · 24h or more, particularly preferably 400 g ^/ m 2 · 24h or more. The upper limit of the moisture permeability of the protective layer 12 may be, for example, 650g ^/ m 2 · 24h. Moisture permeability of the retardation layer 20 is preferably not more than 150g ^/ m 2 · 24h, more preferably not more than 100g ^/ m 2 · 24h, even more preferably not more than 70g ^/ m 2 · 24h, particularly preferably is less than or equal to 50g ^/ m 2 · 24h. Moisture permeability preferably as low retardation layer 20, the lower limit can be, for example, 5g ^/ m 2 · 24h. If the moisture permeability of the protective layer 12 and the retardation layer 20 is within such a range, it is easy to set the above difference in moisture permeability to a desired range. The moisture permeability can be measured according to JIS Z 0208.

The total thickness of the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer is preferably 120 μm or less, and more preferably 100 μm or less. The lower limit of the total thickness can be, for example, 45 μm. A polarizing plate with a retardation layer and an adhesive layer having such a total thickness can have extremely excellent flexibility and bending durability. As a result, the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer can be particularly preferably applied to a curved organic EL display device and / or a bendable or bendable organic EL display device.

The polarizing plate with the retardation layer and the pressure-sensitive adhesive layer may further have another retardation layer (not shown) between the retardation layer 30 and the second pressure-sensitive adhesive layer 40. Another retardation layer is typically a so-called positive C plate in which the refractive index characteristic shows a relationship of nz> nx = ny. By providing such another retardation layer, it is possible to satisfactorily prevent reflection in the oblique direction, and it is possible to widen the viewing angle of the antireflection function.

The retardation layer and the polarizing plate with the pressure-sensitive adhesive layer may further include other optical functional layers. The types, characteristics, numbers, combinations, arrangement positions, and the like of the optical functional layers that can be provided on the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer can be appropriately set according to the purpose. For example, the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer may further have a conductive layer or an isotropic base material with a conductive layer (neither is shown). The conductive layer or the isotropic base material with the conductive layer is typically provided on the outside of the retardation layer 20 (opposite to the polarizing plate 10). When a conductive layer or an isotropic substrate with a conductive layer is provided, the retardation layer and the polarizing plate with an adhesive layer are so-called inner touch panel type input display devices in which a touch sensor is incorporated between the organic EL cell and the polarizing plate. Can be applied to. Further, for example, the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer may further include other retardation layers. The optical characteristics (for example, refractive index characteristics, in-plane retardation, Nz coefficient, photoelastic coefficient), thickness, arrangement position, and the like of other retardation layers can be appropriately set according to the purpose.

The retardation layer and the polarizing plate with the pressure-sensitive adhesive layer may be single-wafered or elongated. As used herein, the term "long" means an elongated shape having a length sufficiently long with respect to the width, and for example, an elongated shape having a length of 10 times or more, preferably 20 times or more with respect to the width. Including. The elongated retardation layer and the polarizing plate with the adhesive layer can be wound in a roll shape.

Hereinafter, the components of the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer will be described in more detail.

B. Polarizing plate B-1. Polarizer As the polarizer 11, any suitable polarizer can be adopted. For example, the resin film forming the polarizer may be a single-layer resin film or a laminated body having two or more layers.

Specific examples of the polarizer composed of a single-layer resin film include a hydrophilic polymer film such as a polyvinyl alcohol (PVA) -based film, a partially formalized PVA-based film, and an ethylene / vinyl acetate copolymer system partially saponified film. Examples thereof include those which have been dyed and stretched with a bicolor substance such as iodine or a bicolor dye, and polyene-based oriented films such as a dehydrated product of PVA and a dehydrogenated product of polyvinyl chloride. Preferably, since the PVA-based film is excellent in optical properties, a polarizer obtained by dyeing a PVA-based film with iodine and uniaxially stretching the film is used.

The dyeing with iodine is performed, for example, by immersing a PVA-based film in an aqueous iodine solution. The draw ratio of the uniaxial stretching is preferably 3 to 7 times. Stretching may be performed after the dyeing treatment or while dyeing. Alternatively, it may be stretched and then dyed. If necessary, the PVA-based film is subjected to a swelling treatment, a cross-linking treatment, a washing treatment, a drying treatment and the like. For example, by immersing the PVA-based film in water and washing it with water before dyeing, it is possible not only to clean the dirt on the surface of the PVA-based film and the blocking inhibitor, but also to swell the PVA-based film to prevent uneven dyeing. Can be prevented.

Specific examples of the polarizer obtained by using the laminate include a laminate of a resin base material and a PVA-based resin layer (PVA-based resin film) laminated on the resin base material, or a resin base material and the resin. Examples thereof include a polarizer obtained by using a laminate with a PVA-based resin layer coated and formed on a base material. The polarizer obtained by using the laminate of the resin base material and the PVA-based resin layer coated and formed on the resin base material is, for example, a resin base material obtained by applying a PVA-based resin solution to the resin base material and drying the resin base material. It is produced by forming a PVA-based resin layer on the resin layer to obtain a laminate of a resin base material and a PVA-based resin layer; and stretching and dyeing the laminate to use the PVA-based resin layer as a polarizer. obtain. In the present embodiment, stretching typically includes immersing the laminate in an aqueous boric acid solution for stretching. Further, stretching may further include, if necessary, stretching the laminate in the air at a high temperature (eg, 95 ° C. or higher) prior to stretching in boric acid aqueous solution. The obtained resin substrate / polarizer laminate may be used as it is (that is, the resin substrate may be used as a protective layer for the polarizer), and the resin substrate is peeled off from the resin substrate / polarizer laminate. Then, an arbitrary appropriate protective layer according to the purpose may be laminated on the peeled surface. Details of the method for producing such a polarizer are described in, for example, Japanese Patent Application Laid-Open No. 2012-73580 and Japanese Patent No. 6470455. The entire description of these publications is incorporated herein by reference.

The thickness of the polarizer is preferably 15 μm or less, more preferably 12 μm or less, still more preferably 10 μm or less, and particularly preferably 8 μm or less. On the other hand, the thickness of the polarizer is preferably 1 μm or more, more preferably 2 μm or more, and further preferably 3 μm or more. When the thickness of the polarizer is in such a range, curling during heating can be satisfactorily suppressed, and good appearance durability during heating can be obtained.

The polarizer preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The simple substance transmittance of the polarizer is, for example, 41.5% to 46.0%, preferably 43.0% to 46.0%, and preferably 44.5% to 46.0%. The degree of polarization of the polarizer is preferably 97.0% or more, more preferably 99.0% or more, and further preferably 99.9% or more.

B-2. Protective Layer The visible side protective layer 12 and the inner protective layer 13 (if any) are each composed of any suitable film that can be used as a protective layer for the polarizer. Typical materials constituting the inner protective layer 13 include cycloolefin resins such as polycarbonate, (meth) acrylic resins, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and polyester resins such as polyethylene terephthalate (PEN). Examples thereof include polyolefin resins such as polyethylene and polycarbonate resins. A typical example of the (meth) acrylic resin is a (meth) acrylic resin having a lactone ring structure. Examples of the (meth) acrylic resin having a lactone ring structure include JP-A-2000-230016, JP-A-2001-151814, JP-A-2002-120326, JP-A-2002-254544, and JP-A-2005. It is described in the publication of -146084. These publications are incorporated herein by reference. The inner protective layer 13 (if present) is preferably composed of a cycloolefin-based resin. Typical examples of the material constituting the visible side protective layer 12 include a cellulosic resin such as triacetyl cellulose (TAC) and a resin capable of forming a microporous film (for example, a polyurethane resin).

In one embodiment, the protective layer (particularly, the visible side protective layer) may contain an ultraviolet absorber. By containing the UV absorber in the protective layer, the deterioration of the organic EL panel is further improved by the synergistic effect with the effect of the first pressure-sensitive adhesive layer or the second pressure-sensitive adhesive layer containing the UV absorber. Can be prevented. The content of the ultraviolet absorber in the protective layer is preferably 0.01% by weight to 10% by weight, more preferably 0.05% by weight to 7% by weight.

The retardation layer and the polarizing plate with the pressure-sensitive adhesive layer are typically arranged on the visible side of the organic EL display device as described later, and the protective layer 12 is arranged on the visible side thereof. Therefore, the protective layer 12 may be subjected to surface treatment such as hard coat treatment, antireflection treatment, anti-sticking treatment, and anti-glare treatment, if necessary. Further / or, if necessary, the protective layer 12 is provided with a process for improving visibility when visually recognizing through polarized sunglasses (typically, a (elliptical) circularly polarized light function is provided, and an ultra-high phase difference is provided. May be given). By performing such a process, excellent visibility can be realized even when the display screen is visually recognized through a polarized lens such as polarized sunglasses. Therefore, the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer can be suitably applied to an organic EL display device that can be used outdoors.

The thickness of the protective layer 12 is preferably 10 μm to 80 μm, more preferably 15 μm to 70 μm, and even more preferably 20 μm to 50 μm. When the surface treatment is applied, the thickness of the protective layer 12 is a thickness including the thickness of the surface treatment layer.

The protective layer 13 is preferably optically isotropic in one embodiment. As used herein, "optically isotropic" means that the in-plane retardation Re (550) is 0 nm to 10 nm and the thickness direction retardation Rth (550) is -10 nm to +10 nm. Say. The thickness of the protective layer 13 can also be appropriately set according to the desired moisture permeability. The thickness of the protective layer 13 is preferably 10 μm to 80 μm, more preferably 20 μm to 70 μm, and even more preferably 30 μm to 50 μm. As mentioned above, the protective layer 13 may be preferably omitted.

C. Phase difference layer The phase difference layer 20 may be a single layer or may have a laminated structure (substantially a two-layer structure).

When the retardation layer 20 is a single layer, the retardation layer 20 can typically function as a λ / 4 plate. The retardation layer is typically provided to impart antireflection characteristics to an organic EL display device. The retardation layer typically shows a relationship in which the refractive index characteristic is nx> ny = nz. The in-plane retardation Re (550) of the retardation layer is preferably 100 nm to 190 nm, more preferably 110 nm to 170 nm, and even more preferably 120 nm to 160 nm. Here, "ny = nz" includes not only the case where ny and nz are completely equal, but also the case where they are substantially equal. Therefore, ny> nz or ny <nz may occur within a range that does not impair the effects of the present invention.

The Nz coefficient of the retardation layer is preferably 0.9 to 1.5, and more preferably 0.9 to 1.3. By satisfying such a relationship, an organic EL display device having a very excellent reflected hue can be obtained.

When the retardation layer is a single layer, the retardation layer preferably exhibits a reverse dispersion wavelength characteristic in which the retardation value increases with the wavelength of the measurement light. In this case, the Re (450) / Re (550) of the retardation layer is preferably 0.8 or more and less than 1, and more preferably 0.8 or more and 0.95 or less. With such a configuration, very excellent antireflection characteristics can be realized.

The angle formed by the slow axis of the retardation layer and the absorption axis of the polarizer is preferably 40 ° to 50 °, more preferably 42 ° to 48 °, and even more preferably about 45 °. When the angle is in such a range, an organic EL display device having very excellent antireflection characteristics can be obtained by using the retardation layer as a λ / 4 plate as described above.

The retardation layer may be made of any suitable material as long as the above characteristics can be satisfied. Specifically, the retardation layer may be a stretched film of a resin film, or may be an orientation-solidifying layer of a liquid crystal compound (hereinafter, a liquid crystal alignment solidification layer).

When the retardation layer is a stretched film of a resin film, typical examples of the resin constituting the resin film include a polycarbonate-based resin or a polyester carbonate-based resin (hereinafter, may be simply referred to as a polycarbonate-based resin). As the polycarbonate-based resin, any suitable polycarbonate-based resin can be used as long as the desired moisture permeability can be obtained. For example, the polycarbonate-based resin contains a structural unit derived from a fluorene-based dihydroxy compound, a structural unit derived from an isosorbide-based dihydroxy compound, an alicyclic diol, an alicyclic dimethanol, di, tri or polyethylene glycol, and an alkylene. Includes structural units derived from at least one dihydroxy compound selected from the group consisting of glycols or spiroglycols. Preferably, the polycarbonate-based resin is a structural unit derived from a fluorene-based dihydroxy compound, a structural unit derived from an isosorbide-based dihydroxy compound, a structural unit derived from an alicyclic dimethanol, and / or di, tri or polyethylene glycol. Includes structural units derived from; more preferably structural units derived from fluorene dihydroxy compounds, structural units derived from isosorbide dihydroxy compounds, and structural units derived from di, tri or polyethylene glycol. .. The polycarbonate-based resin may contain structural units derived from other dihydroxy compounds, if necessary. The retardation layer can be formed by stretching a film made of the above-mentioned polycarbonate resin under arbitrary suitable stretching conditions. For details on the method for forming the polycarbonate resin and the retardation layer, see, for example, JP-A-2014-10291, JP-A-2014-26266, JP-A-2015-212816, JP-A-2015-212817. It is described in JP-A-2015-212818, JP-A-2017-54093, and JP-A-2018-60014. The descriptions in these publications are incorporated herein by reference.

When the retardation layer is a liquid crystal oriented solidified layer, the difference between nx and ny of the obtained retardation layer can be remarkably increased as compared with the non-liquid crystal material by using the liquid crystal compound, so that the desired surface can be obtained. The thickness of the retardation layer for obtaining the inner retardation can be remarkably reduced. As a result, it is possible to further reduce the thickness of the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer (as a result, the organic EL display device). As used herein, the term "aligned solidified layer" refers to a layer in which a liquid crystal compound is oriented in a predetermined direction within the layer and the oriented state is fixed. The "oriented solidified layer" is a concept including an oriented cured layer obtained by curing a liquid crystal monomer. In the present embodiment, the rod-shaped liquid crystal compounds are typically oriented in a state of being aligned in the slow axis direction of the retardation layer (homogeneous orientation). Specific examples of the liquid crystal compound and details of the method for forming the liquid crystal oriented solidified layer are described in, for example, JP-A-2006-163343 and JP-A-2006-178389. The descriptions in these publications are incorporated herein by reference.

The thickness of the retardation layer can typically be set to a thickness that can adequately function as a λ / 4 plate. When the retardation layer is a stretched film of a resin film, the thickness of the retardation layer can be, for example, 10 μm to 60 μm. When the retardation layer is a liquid crystal oriented solidification layer, the thickness of the retardation layer can be, for example, 1 μm to 5 μm.

When the retardation layer has a laminated structure, the retardation layer typically has a two-layer structure of a first liquid crystal oriented solidified layer and a second liquid crystal oriented solidified layer. In this case, either one of the first liquid crystal oriented solidified layer or the second liquid crystal oriented solidified layer can function as a λ / 2 plate, and the other can function as a λ / 4 plate. Here, the case where the first liquid crystal oriented solidified layer can function as a λ / 2 plate and the second liquid crystal oriented solidified layer can function as a λ / 4 plate will be described, but these may be reversed. .. The thickness of the first liquid crystal oriented solidified layer can be adjusted so as to obtain a desired in-plane phase difference of the λ / 2 plate, and can be, for example, 2.0 μm to 4.0 μm. The thickness of the second liquid crystal oriented solidified layer can be adjusted so as to obtain the desired in-plane phase difference of the λ / 4 plate, and can be, for example, 1.0 μm to 2.5 μm. The in-plane retardation Re (550) of the first liquid crystal oriented solidified layer is preferably 200 nm to 300 nm, more preferably 230 nm to 290 nm, and further preferably 250 nm to 280 nm. As described above, the in-plane retardation Re (550) of the second liquid crystal oriented solidified layer is preferably 100 nm to 190 nm, more preferably 110 nm to 170 nm, and further preferably 120 nm to 160 nm. The angle formed by the slow axis of the first liquid crystal oriented solidified layer and the absorption axis of the polarizer is preferably 10 ° to 20 °, more preferably 12 ° to 18 °, and even more preferably about 15 °. Is. The angle formed by the slow axis of the second liquid crystal oriented solidified layer and the absorption axis of the polarizer is preferably 70 ° to 80 °, more preferably 72 ° to 78 °, and even more preferably about 75 °. Is. With such a configuration, it is possible to obtain characteristics close to the ideal reverse wavelength dispersion characteristic, and as a result, it is possible to realize extremely excellent antireflection characteristics.

D. First pressure-sensitive adhesive layer and second pressure-sensitive adhesive layer D-1. Outline of First Adhesive Layer and Second Adhesive Layer The first adhesive layer and the second adhesive layer may be composed of the same adhesive, or may be composed of different adhesives. You may. Composition of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer (for example, type of base polymer (polarity, Tg, softness), molecular weight), cross-linking structure (for example, type of cross-linking agent, distance between cross-linking points (molecular weight between cross-linking points), By adjusting the crosslink density) and the like, the effect of the embodiment of the present invention (for example, durability in a high temperature and high humidity environment) can be made more remarkable.

The thickness of the first pressure-sensitive adhesive layer is preferably 2 μm to 15 μm, more preferably 3 μm to 12 μm, and even more preferably 5 μm to 10 μm. The thickness of the second pressure-sensitive adhesive layer is preferably 10 μm to 50 μm, more preferably 10 μm to 30 μm, and even more preferably 10 μm to 20 μm. When the thickness of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer is within such a range, the durability in a high-temperature and high-humidity environment is due to the synergistic effect of the composition of the protective layer and the retardation layer. It is possible to realize a polarizing plate with a retardation layer and an adhesive layer, which is excellent in quality and whose decolorization is remarkably suppressed when applied to an organic EL display device.

The solubility of the first pressure-sensitive adhesive layer (substantially the pressure-sensitive adhesive constituting the first pressure-sensitive adhesive layer) in ethyl acetate at 25 ° C. is preferably 2 g / 100 g to 70 g / 100 g, more preferably 10 g. / 100 g to 60 g / 100 g, more preferably 15 g / 100 g to 60 g / 100 g. When the solubility of the first pressure-sensitive adhesive layer is within such a range, the ultraviolet absorber can be appropriately incorporated into the first pressure-sensitive adhesive layer.

The molar extinction coefficient of the first pressure-sensitive adhesive layer at a wavelength of 380 nm is preferably 400 L / (mol · cm) or more, more preferably 500 L / (mol · cm) or more, and even more preferably 600 L / (mol · cm) or more. cm) or more. On the other hand, the molar extinction coefficient is preferably 1500 mol / (L · cm) or less. When the molar extinction coefficient is in such a range, the amount of the ultraviolet absorber for obtaining the desired ultraviolet absorbing ability can be reduced. As a result, the adverse effect of the ultraviolet absorber can be reduced, and excellent durability can be realized in a high temperature and high humidity environment. The molar extinction coefficient is a value obtained by the following formula.
Molar extinction coefficient = A / (c × l)
(In the formula, A represents the absorbance, c represents the molar concentration (mol / L), and l represents the cell thickness (cm).)

The gel fraction of the first pressure-sensitive adhesive layer is preferably 60% or more, more preferably 60% to 90%, and even more preferably 80% to 90%. When the gel fraction is in such a range, foaming and peeling can be suppressed in a high temperature and high humidity environment, and deterioration of the appearance can be suppressed. The gel fraction is determined by (dry weight after immersion / dry weight before immersion) × 100 when the crosslinked pressure-sensitive adhesive is immersed in a predetermined solvent (for example, ethyl acetate) for 6 days and then dried.

Hereinafter, the constituent material (adhesive composition) will be described by combining the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer as a pressure-sensitive adhesive layer.

D-2. Constituent materials for the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer D-2-1. The base polymer pressure-sensitive adhesive layer is typically formed from a pressure-sensitive adhesive composition containing a (meth) acrylic polymer, a urethane-based polymer, a silicone-based polymer, or a rubber-based polymer as the base polymer. When a (meth) acrylic polymer is used as the base polymer, the pressure-sensitive adhesive layer is formed from, for example, a pressure-sensitive adhesive composition containing the (meth) acrylic polymer (A). The (meth) acrylic polymer (A) contains an alkyl (meth) acrylate as a main component.

<(Meta) acrylic polymer (A)>
As described above, the (meth) acrylic polymer (A) contains an alkyl (meth) acrylate as a main component. The alkyl (meth) acrylate is preferably 50% by weight or more in all the monomer components forming the (meth) acrylic polymer (A) from the viewpoint of improving the adhesiveness of the pressure-sensitive adhesive layer, and the alkyl (meth) acrylate is said. ) It can be arbitrarily set as the remainder of the monomer other than acrylate. In addition, (meth) acrylate means acrylate and / or methacrylate.

Examples of the alkyl (meth) acrylate constituting the main skeleton of the (meth) acrylic polymer (A) include linear or branched alkyl groups having 1 to 18 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, an amyl group, a hexyl group, a cyclohexyl group, a heptyl group, a 2-ethylhexyl group, an isooctyl group, a nonyl group and a decyl group. , Isodecyl group, dodecyl group, isomyristyl group, lauryl group, tridecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group and the like. Alkyl (meth) acrylates can be used alone or in combination. The average carbon number of the alkyl group is preferably 3 to 10, and more preferably 3 to 6.

The (meth) acrylic polymer (A) may contain a copolymerization monomer such as a carboxyl group-containing monomer (a1) and a hydroxyl group-containing monomer (a2) as a monomer component in addition to the alkyl (meth) acrylate. Good. The copolymerizable monomers can be used alone or in combination.

The carboxyl group-containing monomer (a1) is a compound containing a carboxyl group in its structure and containing a polymerizable unsaturated double bond such as a (meth) acryloyl group or a vinyl group. Examples of the carboxyl group-containing monomer include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Among these, acrylic acid is preferable from the viewpoint of improving copolymerizability, price, and adhesive properties of the pressure-sensitive adhesive layer.

When a carboxyl group-containing monomer (a1) is used as the monomer component, the content of the carboxyl group-containing monomer (a1) is usually 0.01% by weight in all the monomer components forming the (meth) acrylic polymer (A). It is 10% by weight or less.

The hydroxyl group-containing monomer (a2) is a compound containing a hydroxyl group in its structure and containing a polymerizable unsaturated double bond such as a (meth) acryloyl group or a vinyl group. Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and 8-hydroxyoctyl ( Examples thereof include hydroxyalkyl (meth) acrylates such as 10-hydroxydecyl (meth) acrylate and 12-hydroxylauryl (meth) acrylate; (4-hydroxymethylcyclohexyl) -methylacrylate and the like. Among these, 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are preferable from the viewpoint of improving the durability of the pressure-sensitive adhesive layer.

When a hydroxyl group-containing monomer (a2) is used as the monomer component, the content of the hydroxyl group-containing monomer (a2) is usually 0.01% by weight in all the monomer components forming the (meth) acrylic polymer (A). It is 10% by weight or less, and more preferably 0.05% by weight to 3% by weight.

Other copolymerization monomer (a3) may be further used as the monomer component. The other copolymerizable monomer (a3) has a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group. By using the other copolymerization monomer (a3), the adhesiveness and heat resistance of the pressure-sensitive adhesive layer can be improved. The other copolymerization monomer (a3) can be used alone or in combination.

By using an amino group-containing monomer and an amide group-containing monomer as the other copolymerization monomer (a3), the adhesion of the pressure-sensitive adhesive layer can be improved. The amino group-containing monomer is, for example, N, N-dimethylaminoethyl (meth) acrylate or N, N-dimethylaminopropyl (meth) acrylate. The amide group-containing monomer includes, for example, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropylacrylamide, N-methyl (meth) acrylamide, and N-butyl ( Meta) acrylamide, N-hexyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylol-N-propane (meth) acrylamide, aminomethyl (meth) acrylamide, aminoethyl (meth) acrylamide, mercaptomethyl (meth) ) Acrylamides such as acrylamide and mercaptoethyl (meth) acrylamide; N-acrylloyl heterocyclic monomers such as N- (meth) acryloylmorpholin, N- (meth) acryloylpiperidin and N- (meth) acryloylpyrrolidin It is an N-vinyl group-containing lactam-based monomer such as N-vinylpyrrolidone and N-vinyl-ε-caprolactam.

Other copolymerization monomers (a3) include, for example, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, and (meth). (Meta) acrylic acid alkoxyalkyl esters such as 3-methoxypropyl acrylate, 3-ethoxypropyl (meth) acrylate, 4-methoxybutyl (meth) acrylate, 4-ethoxybutyl (meth) acrylate; 2-( Cyclic polymerizable monomer such as methyl allyloxymethyl) acrylate; epoxy group-containing monomer such as (meth) glycidyl acrylate, methyl glycidyl (meth) acrylate; sulfonic acid group-containing monomer such as sodium vinyl sulfonate; phosphoric acid Group-containing monomer; (meth) acrylate having an alicyclic hydrocarbon group such as cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate; phenyl (meth) acrylate, (meth). ) (Meta) acrylic acid esters having aromatic hydrocarbon groups such as phenoxyethyl acrylate and benzyl (meth) acrylate; vinyl esters such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene and vinyl toluene Olefins or dienes such as ethylene, propylene, butadiene, isoprene, isobutylene; vinyl ethers such as vinylalkyl ethers; vinyl chloride can be used.

The content of the other copolymerization monomer (a3) in the (meth) acrylic polymer is preferably 20% by weight or less.

The (meth) acrylic polymer is, for example, a copolymer of butyl acrylate, acrylic acid, hydroxybutyl acrylate, hydroxyethyl acrylate and acryloyl morpholine, a copolymer of butyl acrylate, acrylic acid and hydroxyethyl acrylate, and butyl acrylate. It can be a copolymer of hydroxybutyl acrylate, or a polymer of butyl acrylate, acrylic acid, hydroxybutyl acrylate, N-vinylpyrrolidone, and phenoxyethyl acrylate.

In one embodiment, the (meth) acrylic polymer (A) may contain acrylic acid in the monomer component, preferably 0.1% by weight to 7% by weight, more preferably 2% by weight to 6% by weight. ..

The weight average molecular weight Mw of the (meth) acrylic polymer (A) is, for example, 200,000 to 3 million, preferably 1 million to 2.5 million, and more preferably 1.2 million to 2.5 million. When the weight average molecular weight Mw is in such a range, a pressure-sensitive adhesive layer having excellent durability (particularly heat resistance) can be obtained. If the weight average molecular weight Mw exceeds 3 million, an increase in viscosity and / or gelation during polymer polymerization may occur.

D-2-2. Reactive functional group-containing silane coupling agent The pressure-sensitive adhesive composition can contain a reactive functional group-containing silane coupling agent. In the reactive functional group-containing silane coupling agent, the reactive functional group is typically a functional group other than the acid anhydride group. Examples of the functional group other than the acid anhydride group include an epoxy group, a mercapto group, an amino group, an isocyanate group, an isocyanurate group, a vinyl group, a styryl group, an acetoacetyl group, a ureido group, a thiourea group and a (meth) acrylic. Examples include groups, heterocyclic groups, and combinations thereof. Reactive functional group-containing silane coupling agents can be used alone or in combination.

When the reactive functional group-containing silane coupling agent is blended in the pressure-sensitive adhesive composition, the blending amount of the reactive functional group-containing silane coupling agent is usually 100 parts by weight of the (meth) acrylic polymer (A). 0.001 part by weight or more and 5 parts by weight or less.

D-2-3. Cross-linking agent The pressure-sensitive adhesive composition can contain a cross-linking agent. As the cross-linking agent, an organic cross-linking agent, a polyfunctional metal chelate, or the like can be used. Examples of the organic cross-linking agent include isocyanate-based cross-linking agents, peroxide-based cross-linking agents, epoxy-based cross-linking agents, and imine-based cross-linking agents. A polyfunctional metal chelate is one in which a polyvalent metal is covalently or coordinated to an organic compound. When the pressure-sensitive adhesive composition is a radiation-curable type, a polyfunctional monomer can be used as a cross-linking agent. Crosslinkers can be used alone or in combination.

When the cross-linking agent is blended in the pressure-sensitive adhesive composition, the blending amount of the cross-linking agent is usually 0.01 parts by weight or more and 15 parts by weight or less with respect to 100 parts by weight of the (meth) acrylic polymer (A).

When the isocyanate-based cross-linking agent is blended in the pressure-sensitive adhesive composition, the blending amount of the isocyanate-based cross-linking agent is usually 0.01 parts by weight or more and 15 parts by weight or less with respect to 100 parts by weight of the (meth) acrylic polymer.

D-2-4. Ultraviolet absorber In the embodiment of the present invention, the pressure-sensitive adhesive layer (substantially, the pressure-sensitive adhesive composition) contains an ultraviolet absorber as described above. As described above, the ultraviolet absorber may be contained in the first pressure-sensitive adhesive layer or may be contained in the second pressure-sensitive adhesive layer. The UV absorber is preferably contained in the first pressure-sensitive adhesive layer. The content of the ultraviolet absorber in the pressure-sensitive adhesive layer is as described in the above item A. As the ultraviolet absorber, any suitable ultraviolet absorber may be adopted. Examples of the ultraviolet absorber include a benzotriazole-based ultraviolet absorber, a triazine-based ultraviolet absorber, and a benzophenone-based ultraviolet absorber. The ultraviolet absorber may be used alone or in combination of two or more. Further, the UV absorber may be used in combination with an antioxidant.

D-2-5. The radical generator pressure-sensitive adhesive layer (substantially, the pressure-sensitive adhesive composition) may contain a radical generator. Examples of the radical generator include those that generate radicals by irradiation with visible light or ultraviolet rays having a wavelength shorter than 450 nm. Specific examples include hydroxyketones, benzyldimethylketals, aminoketones, acylphosphine oxides, benzophenones, and trichloromethyl group-containing triazine derivatives. The radical generator may be used alone or in combination of two or more. The radical generator can be a peroxide-based cross-linking agent. The radical generator is preferably 0.01 parts by weight to 2 parts by weight, more preferably 0.01 parts by weight to 1 part by weight, based on 100 parts by weight of the base polymer ((meth) acrylic polymer (A)). Can be used in proportions. Within such a range, it is easy to adjust workability, cross-linking stability, and the like.

D-2-6. Additives The pressure-sensitive adhesive composition may contain (meth) acrylic oligomers and / or ionic compounds. Moreover, the pressure-sensitive adhesive composition may contain an additive. Specific examples of additives include powders such as colorants and pigments, dyes, surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antiaging agents, light stabilizers, and polymerizations. Prohibition agents, inorganic or organic fillers, metal powders, particulates, foils and the like. Further, a redox system to which a reducing agent is added may be adopted within a controllable range. The type, number, combination, content, etc. of additives can be appropriately set according to the purpose. The content of the additive is preferably 5 parts by weight or less, more preferably 3 parts by weight or less, and further preferably 1 part by weight or less with respect to 100 parts by weight of the (meth) acrylic polymer (A). is there.

E. Image display device The polarizing plate with the retardation layer and the pressure-sensitive adhesive layer according to the above items A to D can be applied to an organic EL display device. Therefore, an embodiment of the present invention includes an organic EL display device using such a retardation layer and a polarizing plate with an adhesive layer. The organic EL display device according to the embodiment of the present invention includes the retardation layer and the polarizing plate with an adhesive layer according to the above items A to D on the visible side thereof. The retardation layer and the polarizing plate with the pressure-sensitive adhesive layer are laminated so that the retardation layer is on the organic EL cell side (the polarizing plate is on the visual recognition side). In one embodiment, the organic EL display device has a curved shape (substantially a curved display screen) and / or is bendable or bendable. As described above, when the retarding layer and the polarizing plate with the adhesive layer are applied to the organic EL display device, the present inventors have a phase difference due to ammonia (substantially ammonium ions) generated from the organic EL panel. A new problem of decolorization of the layer and the polarizing plate with the pressure-sensitive adhesive layer was discovered, and the problem was solved by the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer according to the above items A to D. That is, in the organic EL display device, the effect of the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer according to the embodiment of the present invention is remarkable.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. The measurement method of each characteristic is as follows. Unless otherwise specified, "parts" and "%" in Examples and Comparative Examples are based on weight.
(1) Thickness The thickness of 10 μm or less was measured using an interference film thickness meter (manufactured by Otsuka Electronics Co., Ltd., product name “MCPD-3000”). The thickness exceeding 10 μm was measured using a digital micrometer (manufactured by Anritsu, product name “KC-351C”).
(2) Single-unit transmittance and polarization degree The single-unit transmittance Ts and parallel transmittance measured using an ultraviolet-visible spectrophotometer (“LPF-2000” manufactured by Otsuka Electronics Co., Ltd.) for the polarizing plates used in Examples and Comparative Examples. The Tp and the orthogonal transmittance Tc were defined as the polarizers Ts, Tp and Tc, respectively. These Ts, Tp and Tc are Y values measured by the JIS Z8701 2 degree field of view (C light source) and corrected for luminosity factor. From the obtained Tp and Tc, the degree of polarization P was determined by the following formula.
Polarization degree P (%) = {(Tp-Tc) / (Tp + Tc)} ^1/2 × 100
(3) Moisture Permeability Measured according to JIS Z 0208. Specifically, the protective layer or the retardation layer (the film constituting the layer) used in Examples and Comparative Examples was cut out in a circle of 10 cmΦ and used as a measurement sample. The moisture permeability of this measurement sample was measured using "MOCON" manufactured by Hitachi, Ltd. under the test conditions of 40 ° C. and 92% RH.
(4) Transmittance at a Wavelength of 380 nm The retardation layer and the polarizing plate with the pressure-sensitive adhesive layer obtained in Examples and Comparative Examples were cut out to a predetermined size and used as a measurement sample. This measurement sample was attached to a measuring jig via a second pressure-sensitive adhesive layer, and measured at a wavelength of 380 nm using a spectrophotometer (product name: LPF-2000, manufactured by Otsuka Electronics Co., Ltd.).
(5) Ammonia decolorization test 10 g of a 10% aqueous ammonia solution was placed in a glass bottle (cylindrical shape having a diameter of 30 mm and a depth of 50 mm). At this time, the distance from the liquid level of the aqueous ammonia solution to the mouth (upper end) of the glass bottle was about 30 mm. The polarizing plate with the retardation layer and the pressure-sensitive adhesive layer obtained in Examples and Comparative Examples was cut out to a size of 15 mm × 15 mm and used as a measurement sample. The measurement sample was attached to the edge of the mouth of the glass bottle via the second adhesive layer so that the mouth of the glass bottle was completely covered with this measurement sample and steam did not leak through the gap. The glass bottle covered with the measurement sample was heated at 60 ° C. for 2 hours. (In effect, a polarizer) retardation layer and the adhesive layer-attached polarizing plate _{P 0} the polarization degree before heating, the polarization degree after heating as _{P 20,} the formula: [Delta] P from ΔP _{= P} 20 -P ₀ Was calculated and evaluated according to the following criteria. The smaller ΔP is, the more the decolorization due to ammonia is suppressed.
Excellent: ΔP exceeds -0.1% (close to zero)
Good: ΔP is -40% to -0.1%
Unacceptable: ΔP is -99.0% to -40%
Defective: ΔP is less than -99.0% (close to -100%)
(6) Durability The polarizing plate with the retardation layer and the pressure-sensitive adhesive layer obtained in Examples and Comparative Examples was cut out to a size of 300 mm × 220 mm, and a non-alkali glass plate was passed through a second pressure-sensitive adhesive layer using a laminator. (Manufactured by Corning Inc., trade name "EAGLE XG", thickness 70 μm). Then, autoclave treatment was performed at 50 ° C. and 0.5 MPa for 15 minutes to completely adhere the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer to the non-alkali glass to prepare a measurement sample. After subjecting this measurement sample to a treatment (heating test) for 500 hours in an atmosphere of 85 ° C. and a treatment (humidification test) for 500 hours in an atmosphere of 65 ° C./95% RH, the retardation layer and adhesion The appearance between the polarizing plate with the agent layer and the glass was visually evaluated according to the following criteria.
Excellent: No change in appearance such as foaming or peeling Good: Slight peeling or foaming on the edges, but no practical problem Acceptable: Peeling or foaming on the edges, but special use If not, there is no problem in practical use. Defective: There is significant peeling at the end, and there is a problem in practical use.

[Manufacturing Example 1: Fabrication of Polarizing Plate]
(Making a polarizer)
As the thermoplastic resin base material, an amorphous isophthalic copolymerized polyethylene terephthalate film (thickness: 100 μm) having a long shape, a water absorption rate of 0.75%, and a Tg of about 75 ° C. was used. One side of the resin base material was corona-treated.
100 weight of PVA-based resin in which polyvinyl alcohol (polymerization degree 4200, saponification degree 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "Gosefimer Z410") are mixed at a ratio of 9: 1. A PVA aqueous solution (coating solution) was prepared by dissolving 13 parts by weight of potassium iodide in water.
The PVA aqueous solution was applied to the corona-treated surface of the resin base material and dried at 60 ° C. to form a PVA-based resin layer having a thickness of 13 μm to prepare a laminate.
The obtained laminate was uniaxially stretched at the free end 2.4 times in the longitudinal direction (longitudinal direction) between rolls having different peripheral speeds in an oven at 130 ° C. (aerial auxiliary stretching treatment).
Next, the laminate was immersed in an insolubilizing bath at a liquid temperature of 40 ° C. (an aqueous boric acid solution obtained by blending 4 parts by weight of boric acid with 100 parts by weight of water) for 30 seconds (insolubilization treatment).
Next, the finally obtained polarizing film was placed in a dyeing bath having a liquid temperature of 30 ° C. (an aqueous iodine solution obtained by mixing iodine and potassium iodide in a weight ratio of 1: 7 with respect to 100 parts by weight of water). Immersion was carried out for 60 seconds while adjusting the concentration so that the simple substance transmittance (Ts) was 43.0% (dyeing treatment).
Then, it was immersed in a cross-linked bath at a liquid temperature of 40 ° C. (an aqueous boric acid solution obtained by blending 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with respect to 100 parts by weight of water) for 30 seconds. (Crossing treatment).
Then, while immersing the laminate in a boric acid aqueous solution (boric acid concentration 4.0% by weight, potassium iodide 5.0% by weight) at a liquid temperature of 70 ° C., the rolls having different peripheral speeds are subjected to the longitudinal direction (longitudinal direction). ) Was uniaxially stretched so that the total stretching ratio was 5.5 times (underwater stretching treatment).
Then, the laminate was immersed in a washing bath at a liquid temperature of 20 ° C. (an aqueous solution obtained by blending 4 parts by weight of potassium iodide with 100 parts by weight of water) (cleaning treatment).
Then, while drying in an oven kept at 90 ° C., it was brought into contact with a heating roll made of SUS whose surface temperature was kept at 75 ° C. for about 2 seconds (dry shrinkage treatment). The shrinkage rate in the width direction of the laminated body by the drying shrinkage treatment was 5.2%.
In this way, a polarizer having a thickness of 5 μm was formed on the resin base material.

(Preparation of polarizing plate)
An HC-TAC film was attached to the surface of the polarizer of the resin base material / polarizer laminate obtained above via an ultraviolet curable adhesive. Specifically, the curable adhesive was coated so as to have a thickness of 1.0 μm, and bonded using a roll machine. Then, UV light was irradiated from the HC-TAC film side to cure the adhesive. The HC-TAC film is a film in which a hard coat (HC) layer (thickness 7 μm) is formed on a triacetyl cellulose (TAC) film (thickness 25 μm), and the TAC film is attached so as to be on the polarizer side. I matched it. Next, the resin base material was peeled off to obtain a polarizing plate P1 having a structure of a visible side protective layer (HC-TAC film) / a polarizer. Moisture permeability of the HC-TAC film was 427g ^/ m 2 · 24h.

[Manufacturing Example 2: Fabrication of Polarizing Plate]
A polarizing plate P2 having a visible side protective layer (HC-COP film) / polarizer as in Production Example 1 except that an HC-COP film was used instead of the HC-TAC film as the visible side protective layer. Got The HC-COP film is a film in which an HC layer (thickness 2 μm) is formed on a cycloolefin resin (COP) film (thickness 25 μm), and the COP film is bonded so as to be on the polarizer side. Moisture permeability of the HC-COP film was 17g ^/ m 2 · 24h.

[Manufacturing Example 3: Fabrication of Polarizing Plate]
In the same manner as in Production Example 1, an HC-TAC film was attached to the polarizer surface of the resin base material / polarizer laminate. Next, the resin base material is peeled off, and a COP film (thickness 13 μm) is attached to the peeled surface in the same manner as the HC-TAC film, and the visible side protective layer (HC-TAC film) / polarizer / inner protective layer (COP) is attached. A polarizing plate P3 having the structure of a film) was obtained. Moisture permeability of the COP film was 35g ^/ m 2 · 24h.

[Manufacturing Example 4: Fabrication of a retardation film constituting a retardation layer]
(Polyester carbonate-based resin polymerization)
Polymerization was carried out using a batch polymerization apparatus consisting of two vertical reactors equipped with a stirring blade and a reflux condenser controlled at 100 ° C. Bis [9- (2-phenoxycarbonylethyl) fluorene-9-yl] methane 29.60 parts (0.046 mol), isosorbide (ISB) 29.21 parts (0.200 mol), spiroglycol (SPG) 42.28 part (0.139 mol), were charged diphenyl carbonate (DPC) 63.77 parts (0.298 mol) and 1.19 × ^{10 -2} parts of calcium acetate monohydrate as a catalyst (6.78 × ¹⁰ -5 mol) It is. After substituting nitrogen under reduced pressure in the reactor, heating was performed with a heat medium, and stirring was started when the internal temperature reached 100 ° C. The internal temperature was brought to 220 ° C. 40 minutes after the start of the temperature rise, and the depressurization was started at the same time as controlling to maintain this temperature, and the temperature was adjusted to 13.3 kPa 90 minutes after reaching 220 ° C. The phenol vapor produced as a by-product of the polymerization reaction was guided to a reflux condenser at 100 ° C., the monomer component contained in a small amount in the phenol vapor was returned to the reactor, and the uncondensed phenol vapor was guided to a condenser at 45 ° C. for recovery. Nitrogen was introduced into the first reactor and the pressure was once restored to atmospheric pressure, and then the oligomerized reaction solution in the first reactor was transferred to the second reactor. Then, the temperature rise and depressurization in the second reactor were started, and the internal temperature was 240 ° C. and the pressure was 0.2 kPa in 50 minutes. Then, the polymerization was allowed to proceed until the stirring power became a predetermined value. When the predetermined power was reached, nitrogen was introduced into the reactor to repressurize, the produced polyester carbonate-based resin was extruded into water, and the strands were cut to obtain pellets.

(Making a retardation film)
The obtained polyester carbonate-based resin (pellets) was vacuum-dried at 80 ° C. for 5 hours, and then a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., cylinder set temperature: 250 ° C.), T-die (width 200 mm, set temperature: 250). A long resin film having a thickness of 135 μm was prepared by using a film forming apparatus equipped with a chill roll (set temperature: 120 to 130 ° C.) and a winder. The obtained long resin film was stretched in the width direction at a stretching temperature of 133 ° C. and a stretching ratio of 2.8 times to obtain a retardation film having a thickness of 47 μm. The Re (550) of the obtained retardation film was 141 nm, the Re (450) / Re (550) was 0.82, and the Nz coefficient was 1.12. Further, the moisture permeability of the obtained retardation film was 75g ^/ m 2 · 24h.

[Manufacturing Example 5: Preparation of Liquid Crystal Oriented Solidified Layer Constituting a Phase Difference Layer]
After adding 55 parts of the compound represented by the formula (I), 25 parts of the compound represented by the formula (II), and 20 parts of the compound represented by the formula (III) to 400 parts of cyclopentanone (CPN), 60 parts. Warm to ° C and stir to dissolve, and after confirmation of dissolution, return to room temperature, 3 parts of Irgacure 907 (manufactured by BASF Japan Co., Ltd.), 0.2 parts of Megafuck F-554 (manufactured by DIC Co., Ltd.), 0.1 part of p-methoxyphenol (MEHQ) was added, and the mixture was further stirred to obtain a solution. The solution was clear and uniform. The obtained solution was filtered through a 0.20 μm membrane filter to obtain a polymerizable composition. On the other hand, a polyimide solution for an alignment film was applied to a glass substrate having a thickness of 0.7 mm by a spin coating method, dried at 100 ° C. for 10 minutes, and then fired at 200 ° C. for 60 minutes to obtain a coating film. .. The obtained coating film was subjected to a rubbing treatment to form an alignment film. The rubbing treatment was performed using a commercially available rubbing device. The polymerizable composition obtained above was applied to a base material (substantially an alignment film) by a spin coating method, and dried at 100 ° C. for 2 minutes. The obtained coating film was cooled to room temperature and then irradiated with ultraviolet rays at an intensity of 30 ^{mW / cm 2 for 30 seconds using a high-pressure mercury lamp to obtain a liquid crystal oriented solidified layer.} The in-plane retardation Re (550) of the liquid crystal oriented solidified layer was 130 nm. The Re (450) / Re (550) of the liquid crystal oriented solidified layer was 0.851, showing the inverse dispersion wavelength characteristic.

[Production Example 6: Preparation of Adhesive Base Polymer]
A four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler contains 91.5 parts of butyl acrylate, 3 parts of acrylic acid, 0.5 parts of 4-hydroxybutyl acrylate, and 5 parts of acryloyl morpholine. A mixture of monomers to be prepared was charged. Further, 0.1 part of 2,2'-azobisisobutyronitrile was charged to 100 parts of this monomer mixture together with 100 parts of ethyl acetate as a polymerization initiator, and nitrogen gas was introduced with gentle stirring to introduce nitrogen. After the substitution, the liquid temperature in the flask was maintained at around 55 ° C. and the polymerization reaction was carried out for 8 hours to prepare a solution of an acrylic polymer (base polymer A) having a weight average molecular weight (Mw) of 2.5 million.

[Production Example 7: Preparation of Adhesive Base Polymer]
Similar to Production Example 6 except that a monomer mixture containing 94.9 parts of butyl acrylate, 5 parts of acrylic acid and 0.1 part of hydroxyethyl acrylate was used, the acrylic polymer (base polymer B) having Mw 2.3 million. A solution was prepared.

[Production Example 8: Preparation of Adhesive Base Polymer]
A solution of an acrylic polymer (base polymer C) having a Mw of 1.6 million was prepared in the same manner as in Production Example 6 except that a monomer mixture containing 99 parts of butyl acrylate and 1 part of 4-hydroxybutyl acrylate was used.

[Production Example 9: Preparation of Adhesive Base Polymer]
Production Example 6 except that a monomer mixture containing 81.1 parts of butyl acrylate, 0.3 parts of acrylic acid, 0.6 parts of 4-hydroxybutyl acrylate, 3 parts of N-vinylpyrrolidone and 15 parts of phenoxyethyl acrylate was used. In the same manner as above, a solution of an acrylic polymer (base polymer D) having Mw 1.7 million was prepared.

[Example 1]
An ultraviolet absorber, a radical generator, a cross-linking agent, and an antioxidant were added to 100 parts of the base polymer A obtained in Production Example 6 at the ratios shown in Table 1 to prepare a pressure-sensitive adhesive composition. A pressure-sensitive adhesive layer having a thickness of 5 μm was formed from this pressure-sensitive adhesive composition to form a first pressure-sensitive adhesive layer. Further, a radical generator, a cross-linking agent, and an antioxidant were blended with 100 parts of the base polymer B obtained in Production Example 7 at the ratio shown in Example 7 of Table 1 to prepare a pressure-sensitive adhesive composition. .. A pressure-sensitive adhesive layer having a thickness of 15 μm was formed from this pressure-sensitive adhesive composition to form a second pressure-sensitive adhesive layer. The retardation film obtained in Production Example 4 is attached to the surface of the polarizer of the polarizing plate P1 obtained in Production Example 1 via the first pressure-sensitive adhesive layer, and further, the second retardation film is attached to the surface of the retardation film. The pressure-sensitive adhesive layer was provided. In this way, the polarizing plate with the retardation layer and the pressure-sensitive adhesive layer of this example was produced. The obtained retardation layer and the polarizing plate with the pressure-sensitive adhesive layer were subjected to the evaluations (4) to (6) above. The results are shown in Table 1.

[Examples 2 to 14, Comparative Examples 1 to 6, and Reference Example 1]
A pressure-sensitive adhesive composition is prepared according to the formulation shown in Table 1, and a retardation layer and a retardation layer and a combination of a polarizing plate, a retardation film or a liquid crystal oriented solidifying layer, a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer shown in Table 1 are used. A polarizing plate with an adhesive layer was prepared. The obtained retardation layer and the polarizing plate with the pressure-sensitive adhesive layer were subjected to the same evaluation as in Example 1. The results are shown in Table 1. The liquid crystal oriented solidified layer (Example 4) was transferred from the base material to the surface of the polarizer via the first pressure-sensitive adhesive layer. In addition, 0.2 parts of an epoxy group-containing silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KBM-403") was blended with 100 parts of the base polymer in all the pressure-sensitive adhesive compositions.

The names, abbreviations, etc. in Table 1 are as follows.
"Resin": Phase difference film "Liquid crystal": Liquid crystal oriented solidified layer "AA": Acrylic acid in the base polymer of the adhesive "Tinosorb S": Ultraviolet absorber (manufactured by BASF, trade name "Tinosorb S")
"Tinuvin 460": UV absorber (manufactured by BASF, trade name "Tinuvin 460")
"Tinuvin 928": UV absorber (manufactured by BASF, trade name "Tinuvin 928")
"LA-F70": UV absorber (manufactured by ADEKA CORPORATION, product name "ADEKA STUB LA-F70")
"C / L": Trimethylolpropane / tolylene diisocyanate adduct (manufactured by Tosoh Corporation, trade name "Coronate L")
"D110N": Trimethylolpropane / xylylene diisocyanate adduct (manufactured by Mitsui Chemicals, trade name "Takenate D110N")

[Evaluation]
As is clear from Table 1, according to the embodiment of the present invention, the phase difference is excellent in ultraviolet absorption ability and excellent durability in a high temperature and high humidity environment (specifically, bubbles are suppressed). A polarizing plate with a layer and an adhesive layer can be obtained. Further, the retardation layer and the polarizing plate with the pressure-sensitive adhesive layer of the examples have an advantage that the degree of polarization hardly changes (that is, does not decolorize) even when exposed to ammonia. In Example 14 in which the ultraviolet absorber was introduced only into the second pressure-sensitive adhesive layer, some deterioration was observed in the retardation layer. Further, as is clear from Reference Example 1, it was found that the effect of containing the ultraviolet absorber in the pressure-sensitive adhesive layer is an effect obtained in a configuration in which the polarizing plate has a protective layer only on the visual side (however, polarized light). In a configuration in which the plate has protective layers on both sides, it is not denied that the pressure-sensitive adhesive layer contains an ultraviolet absorber).

The polarizing plate with the retardation layer and the pressure-sensitive adhesive layer of the present invention is suitably used as an antireflection circularly polarizing plate for an organic EL display device.

10 Polarizing plate 11 Polarizing element 12 Protective layer 13 Protective layer 20 Phase difference layer 100 Polarizing plate with retardation layer and adhesive layer

Claims (9)

A polarizing plate containing a polarizing element and a protective layer at least on the visible side of the polarizing element, and a retardation layer bonded to the side opposite to the visible side of the polarizing plate via a first pressure-sensitive adhesive layer. It has a second pressure-sensitive adhesive layer arranged as an outermost layer on the opposite side of the retardation layer from the polarizing plate.
The first pressure-sensitive adhesive layer or the second pressure-sensitive adhesive layer contains an ultraviolet absorber and contains an ultraviolet absorber.
The UV absorber content in the first pressure-sensitive adhesive layer or the second pressure-sensitive adhesive layer is 1% by weight to 12% by weight.
The transmittance at a wavelength of 380 nm is 5% or less.
Polarizing plate with retardation layer and adhesive layer. The retardation layer according to claim 1, wherein the polarizing element and the retardation layer are bonded to each other via the first pressure-sensitive adhesive layer, and the first pressure-sensitive adhesive layer contains an ultraviolet absorber. Polarizing plate with adhesive layer. The polarizing plate with a retardation layer and a pressure-sensitive adhesive layer according to claim 1 or 2, wherein the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer contains acrylic acid as a monomer component of the base polymer. The polarizing plate with a retardation layer and an adhesive layer according to claim 3, wherein the acrylic acid content in the monomer component is 0.1% by weight to 7% by weight. The polarizing plate with a retardation layer and a pressure-sensitive adhesive layer according to claim 3 or 4, wherein the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer further contains a radical generator. The polarizing plate with a retardation layer and a pressure-sensitive adhesive layer according to any one of claims 1 to 5, wherein the first pressure-sensitive adhesive layer has a solubility in ethyl acetate at 25 ° C. of 2 g / 100 g to 70 g / 100 g. The polarizing plate with a retardation layer and a pressure-sensitive adhesive layer according to any one of claims 1 to 6, wherein the first pressure-sensitive adhesive layer has a molar extinction coefficient of 400 L / (mol · cm) or more at a wavelength of 380 nm. The moisture permeability of the viewer side protective layer is not less 200g / m 2 · ^24h or more, greater than the moisture permeability of the retardation layer, the retardation layer and the adhesive according to any one of claims 1 to 7 Layered polarizing plate. An organic electroluminescence display device comprising the polarizing plate with the retardation layer and the pressure-sensitive adhesive layer according to any one of claims 1 to 8.

Images